Arc lighting apparatus



July 18, 1'933- J. H. wAGENHoRsT y 1,918,725

ARC LIGHTING APPARATUS Filed Jan. 14, 1929 5 Sheets-'Sheet l /7 /60 a DE? 26 J 4 a E5 EJ J/ as o 40 f 4 4/ 4/ 450 u 4'/ 45h15 25 5 5 45 -z I @oJuly 18, 1933. J. H. WAGENHORST 1,918,725

ARC LIGHTING APPARATUS Filed Jan. 14, 1929 3 Sheets-Sheet 2 www a@@4m/fm Filed Jan. 14, 1929 3 Sheets-Sheet 3 Patented luly 18, 1933PATENT FFHCE JAMES H. .ULGENHORST, OF DETROIT, MICHIGAN ARC LIGHTINGAPPARATUS .Applica-tien filed January 14, 1929.

My invention relates to improvement-s in arc lighting apparatus, and hasto do, more particularly, with an arc lighting unit designed forFlooding a treatment room or other large area With light.

The chief object of my invention is to lprovide an arc lightingapparatus suitable 'tor use in flooding a treatment room with light sothatthe apparatus may be used in situations such as tubercularhospitals, sanitariums, bath houses, athletic training houses, publicschools, or wherever arc light treatment may be beneficially used.

A further object of my invention is to provide such an apparatus, inwhich the arcs are normally located above the heads ot persons in theroom, but can conveniently be brought down within reaching distance torthe purpose of changing the carbons or any repairs that may benecessary.

A further object of my invention is to provide such an apparatus inwhich any 'lumes coming from the arcs may escape upwardly through thereflector and be carried away from the room.

A further object of my invention to provide a simple and inexpensive,but highly eflicient, apparatus of this nature, which is suitable foruse in treating a large num- ,ber of patients at one time in a singleroom, so that, for instance, the apparatus may be used for flooding aplay room with 1 se that the children treated may play while beingsubjected to the light treatment.

. Further objects, and objects ng to details and economies ofconstruction and operation, will. definitely appear troni the detaileddescription to follow. ln one ine, accomplish the objects of my inven onby the devices and means set Yfor in the following specification. h/'Tyinvention clearly deined and pointed out in the appe ded claims. Astructure constituting a preferred embodiment of my invention isillustrated in the accompanying drawings, `forming a part of thisspecification, in which l Figure l is a view in front elevation of anapparatus embodying my invention;

F ig. 2 is an enlarged, vertical, sectional Serial No. 332,470.

view through the upper portion of the apparatus, the lamp-operatingmechanism being shown in side elevation;

is a horizontal sectional View, taken on the line 3 3 of Fig. 2;

a fragmentary, horizontal View,

i at is 1a lien on the line Ll--t of Fig.` 2;

Fig. 5 is a detail, sectional view, taken snbstantiady on the line 5-5of Fig. l;

l. is a detail, sectional view through a holder Vtor the movableelectrodes, taken line (if-6 of Fig. 2; and i" is a detail View, in sideelevation, of the connection between the spider, the upper end of thesupporting column and the spring-litt devices.

in the drawings, the same reference numedi: refer to the same partsthroughout the several views and the sectional views are taken lool'ingin the direction of the arrows at the ends of the section lines.

ln general, my invention consists in proif'iding a central supportingcolumn to which the rellector is fastened. This reflector has a central.opening therein. The lamp mecha-A nism, which may consist of severallamp units, is mounted on a lamp base, which is slidable on the centralsupporting column, and, as it is raised or lowered on the column, thelamp-operating mechanism may move through the central opening in thereiector. l propose to provide a counterpoise carried by the column,which counterbalances the weight of the lamp base and parts supportedthereby, so that it will remain in the position to which adjusted and beraised aml lowered easily. I propose to provide a spider `iastened tothe upper end of vthe central supporting column supporting a reflectordome, which serves to house the lamp-operating mechanism, and the upperedge ot the relector is 'fastened to the lower edge of this dome. Thecounterpoise used may consist of a spring lift device of the type usedfor counterbalancing window sashes, and ccmprising a coil spring and a'flexible strap, 'the lower ends of the flexible straps of such devicesbeing connected to the lamp base. The lamp-operating mechanisms comprisethe lamp frames which are mounted on the base and have tails projectingthrough the base downwardly therefrom, and an ash tray may be secured tothe lower ends of these tails and thus supported atv a suitable distancefrom the lamp base. I also propose to space the lamp base, when inoperative position, from the reflector, so as to provide vent openingsbetween the outer edge of the lamp base and 'the reflector, throughwhich any fumes coming from the arcs may escape upwardly and out throughthe top of the reflector dome, so that such fumes may be carried out ofthe room in this way, and not be directed downwardly upon the patient.

Referring to the accompanying drawings, in which I have illustrated apreferred embodimcnt of my apparatus, the apparatus supported by acentral supporting column 10, which may well be tubular as shown, so asto form a central conduit through which the circuit wires may be broughtto the apparatus. Secured to the upper end of this column there is aspider formed of the radiating arms 11, the inner ends of which are bentupwardly, at 12, and secured by the curved bolts 14 to the clampingmembers 13, which surround the upper end of the column 10, by whichmeans the spider formed from said radiating' arms is attached rigidly tothe upper end of the column. These clamping members 13 have extensions15, lying on opposite sides of the casings 17 of spring lift devices,and these extensions 15 are secured to said casings by the bolts 16.Each of the radiating` arms 11 of the spider has its outer end formedlinto a sector 18, having an inwardly directed finger' 19 lying againstthe next adjacent arm 11, as shown in Fig. 3, and secured thereto byrivets 20. These arms 11, with the sector portions 18, therefore,constitute in effect a spider, having its center secured to thesupporting column, and having at its periphery a ring'to which the upperedge of the reflector dome is secured. The reflector dome comprises asheet metal cylinder 2l, fitting' around the ring formed by the sectorportions 18, and secured thereto by rivets 22. The reflector 23 is i adeof sheet metal and may i e conical or parabolic, as desired, and thisreflector 23 has a central opening therein bordered by the upstandingflange 24, which lits inside the lower edge of the cylindrical reflectordome 21, the latter having an outwardly flaring flange 25, which fitsupon the upper portion of the reflector 23. VIhe lower portion of thereflector dome 21 and the upper portion of the reflector 23 are securedtogether by rivets 2G passing through the parts 24 and 25, as shown inFig. 2.

The spring lift 'devices in the casings I7 are of a type well known inthe trade and used particularly as window sash balances. These comprisea flexible strap 27 wound about a central shaft to which a coil springis connected, so that, as the strap 27 is pulled out and unrolled, thespring is tensioned and tends constantly to rewind the strap. The lowerends of the straps 27 of these spring lift devices are, in the presentinstance, fastened at 28 to a lamp base 29, having a central openingtherein 'through which the supporting column extends. This lamp base isslidable upon the supporting column and the spring lift devices havingthe flexible straps 27 tend to support the lamp base in the position towhich it has been previously adjusted, the spring lift devices servingas counterpoise means for balancing the weight of the lamp base and theparts supported thereby. The lamp base 29 is provided with adownwardly-flaring flange 30, at its outer edge, and spacing lingers 31are fastened to the outer edge of the lamp base by means of angleportions 32 on said fingers, engaging behind the flange 30, and securedthereto by the rivets 33. lVhen the lamp base is in its operativeposition, as shown in Fig. 2, the ends of the fingers 31 contact withthe reflector 23, and space the edge of the lamp base from thereflector, so as to provide ventopenings between the edge of the lampbase and the rellector, through which any fumes coming from the arcs maypass upwardly and thus escape from the reflector and out through the topof the reflector dome, which is open as shown.

Upon the lamp base I mount a plurality of arc lamp units. In this case,three such units are shown mounted upon the base, arranged equidistantlythereon around the central supporting column 10, as shown in Fig. 4.Each of these units comprises a lamp frame 34, substantially rectangularin shape, the bottom member of which is fastened to the lamp base, andprovided with tail members 35 depending therefrom through an opening inthe lamp base. The lower ends of the tail members 35 are bent laterallyto form the ears 36 to which an ash tray 37 is secured by bolts 38. Thisash tray 37 is preferably provided with a rim flange 91 to preventsparks falling therefrom to the floor. A block 39, of insulatingmaterial., is secured to each pair of tail members 35, and to it aresecured the clamping bars 40, arranged as shown in Fig. 2, so as to beinsulated from each other. The stationary electrodes 43 are clamped tothese clamping bars by the outer clamping members 4l, and the clampingscrews 42, in the manner well understood in this art. In this way, thestationary electrodes are supported by thc tail members 35 between thelamp base 29 and the ash tray 37.

An operating solenoid 44 is resiliently supported from one of the sidemembers of' each lamp frame 34. The core 45, working CIK in thissolenoid, is connected by coil springs 46 to the crossing ends ofelectrode-operating levers 47, whichr are pivoted to the side members ofthe frame l34, at 48. A clutch-operating rod 49 is pivotally connectedto the outer end of each lever 47, the lower end of said rod beingconnected to a clutch 50, having two openings through which the movableelectrodes 51 extend. One of the openings is preferably enlarged, whilethe other is of such size as to bind upon the corresponding electrode51, when the clutch 50 is tilted. Slabs 68, of asbestos boardconstituting both heat and electrical insulation, are fastened by screws69 to the side members of the frame 34, as shown in Fig. 5. Anglebrackets 66 are fastened by bolts 67 to the lower portion of each slabV68, as shown in Fig. 5, and are provided with laterally extending stopmembers 52, which extend beneath the clutches 50, and have openingsthrough which the movable electrodes 51 may pass. The movable electrodes51 are suspended 5 by the clutches 50 and the rods 49 from theelectrode-operating levers 47, and depend through holes 53 in the lampbase 29 in alinement with the stationary electrodes 43.

Referring to Fig. 5, it will be seen thatl the lamp frames 34 arefastened to the base 29 and the ash tray 37 at an inclination to thevertical, the lower ends of said frames being further from the Lcentralsupporting column than the upper ends. Consequently, the electrodes 51and 41 are not aligned vertically, but are in alinement with each otherlin the inclined plane represented by the inclination of the frames 34,as represented in Fig. 45. This inclination of the electrodes makes amore eflicient lighting unit, in that, the light from the craters of thearc is reflected and directed outwardly and is not intercepted by thewalls of the craters. This feature is already described and claimed inmy co-pending application, Serial No. 312,326, iiled the 13th day ofOctober, 1928.

Each lamp unit comprises two pairs of stationary and two pairs ofmovable electrodes. The upper ends of each pair of movable electrodesare clamped within an electrode holder comprising a rear clamping member54, having suitable grooves to receive the electrodes 51, and `providedwith 5 recesses 55. A strip of insulation is applied to the rear face ofthe clamping member 54 between the electrodes, as shown in Fig. 6, andcovering the recesses 55 int-o which the insulation may be pressed. A 0rod guide 57 is next applied to the outer face of this strip ofinsulation and it is provided with projections 58, which line up withthe recesses 55, so that, when this rod guide is clamped in place itwill be 1n- 'l5 sulated from the clamping member 54, but

its projections 58 will press into the insulation and press the latterinto the recesses 55, so as to prevent turning of the rod guide withrespect to the clamping member. A clamping bolt 60 extends through theseparts, having a head 61 which fits against an insulating washer 62applied to the rear face of the rod guide 57. The shank of the clampingbolt 60 extends through an insulating sleevev 63 inserted in an openingin said rod guide, as shown in Fig. 6, and also extends through thesheet of insulation 56 and through the clamping member 54 and the frontclamping member 64. A wing nut 65 is screwed on the outer end of thisclamping bolt. The upper end of Athe rod guide is bent laterally at 59,and this portion has a hole therein through which the rod 49 may slide.

The resistance coils 7() are mounted on the slabs 68 of insulatingmaterial, .as shown in Fig.` 2, and are thus carried by the frame 34 butinsulated therefrom. A dashpot cylinder 71 is mounted on one side memberof the frame 34, and a piston carried by the lower end of the rod 72connected to the end of one of the levers 47, works in the dashpotcylinder 71, in the manner well understood in this art. The upper endsof the rods 49 are, of course, insulated from the ends of the levers 47at the pivotal connection between these rods and the levers.

Each of the three lamp units mounted on the base has its own operatingcircuit controlled by a switch 79 mounted on the under side of the ashtray 37. From the switch 79, Wire 73 leads to the right-hand lowerstationary electrode holder, shown in Fig. 2, thence, the current passesthrough one of the stationary electrodes to the corresponding upperelectrode and from the right-hand electrode holder for the movableelectrodesI through the wire 74 to the left-hand resistance coil 70.From the lower end of this resistance coil the current passes through asshown, the main circuit connections or conductors may well be brought tothe apparatus through this hollow tube, being taken out through thebottom thereof and brought up alongside the tube, as shown in F ig. l,to the ash tray where the conductors are split into three leads 81, onegoing to each of the switches 79, as shown.

The apparatus shown here is adapted i either to be supported from astand on the floor or suspended from the ceiling. In the latter case, anadequate support is provided on the ceiling for the central supportingcolumn 10. I have Ashown the apparatus here as mounted in a standcomprising a central tubular post 82 receiving the lower end lof column10. The post 82 has a series of holes 83 therethrough adapted to receivethe pin 84 by means of which the height of the arc above the floor maybe varied. The legs 85 of the stand have their upper ends connected tothe post 82, at 87, as shown, while their lower ends are .separated andbraced by the brace bars 88, the inner ends of which are connected at 89to the lower end of' the post 82, while the outer ends are connected tothe legs at 90. Casters 86 may be provided on these legs if desired.

The apparatus which I have illustrated and described herein is one whichis adapted to be suspended from the ceiling er supported from the floorin such a way that the arcs are at a distance of approximately nino ortenfeet from the floor, so that by this means a large room may becompletely fiooded with light from the arcs. This makes the apparatusvery convenient a nd suitable for use in hospitals, sanitariums, clubs,tra 1ning houses or other places in which it is desired to subject alarge number of people simultaneously to the beneficial effects of therays of artificial sunlight comingl from the arcs. By means of thecounter-poise and the lamp base supporting the operating mechanism, thebase with the operating mechanism may be easily pulled down so that thecarbons are within reach of an operator, who can then fit the lamp withnew carbons or make any adjustments or repairs that are necessary afterwhich the lamp base can be shoved up to its normal position and will. beheld there by the spring lift devices. As already pointed out, any fumescoming from the arcs, instead of passing outwardly under the lower edgeof the reflector', in which case they might prove disturbing to thepatients being treated with the light, are vented upwardly through thespace between the lamp base and the refiector and through the reflectordome. This lends itself very well to the withdrawal. of these fumes yorheated air through the top of the room by means of an exhaust fan, orotherwise, as may be desired.

InA this apparatus, the reflector' casts a zone of light whichcompletely covers an area about six feet high, so that this sono can beoccupied by as many as sixty to one hundred and fifty people, especiallychildren, who can be treated sin'iultaneously 'ith this apparatus. Theashtray 37 not only functions to catch sparks or ash falling from thecarbon, but also acts to reflect the light 'which might otherwise becast downward. It constitutes a sort of circular refiector by which partof' the light is reflected upwardly toward the conical reflector andthence down upon the lighted zone. Thus, all the light from the arcs isutilized to fill the light zone.

I am aware that the particular embodiment of my invention illustratedherein may be changed considerably without departing from the spirit ofmy invention, and, therefore, I claim my invention broadly as indicatedby tl e appended claims.

lVhat I claim is:

l. An arc lighting apparatus comprising a central supporting post, areflector fixed to and carried by .said post, a lamp base slidable onsaid post, a counterpoise carried by said post and connected to saidbase, electrode-operating mechanism mounted on said base, movableelectrodes depending from said operating mechanism through said base,and stationary electrodes supported below said base in alinement withsaid movable electrodes.

2. An arc lighting apparatus comprising a central supporting post, areflector fixed to and carriedbysaid post, a lamp base slidable on saidpost, a spring-lift device carried by said post and having a fiexiblestrap connected to said base to counterbalance the weight of said baseand parts carried thereby, electrode-operating mechanism supported onsaid base, movable electrodes depending from said operating mechanismthrough said base, and stationary electrodes supported below said basein alinement with said movable electrodes.

3. An arc lighting apparatus comprising a. central supporting post, alamp base slidable on said post, electrode-operating mechanism supportedon said base, movable electrodes depending from said operating mechanismthrough said base, stationary electrodes supported below said base inalinement with said movable electrodes, and a refiector fixed to andcarried by said post with its upper edge normally positioned adjacentthe lamp base and having a central opening through which the operatingmechanism is movable as the base is raised and lowered on the post.

4. An arc lighting apparatus comprising a central supporting post, alamp base slidable on said post, a counterpoise carried by said post andconnected to said base, electrode-operating mechanism supported on saidbase, movable electrodes depending from said operating mechanism throughsaid base, stationary electrodes supported below said base in alinementwith said movable electrodes, and a reflector fixed to and carried bysaid post and having a central opening through which the operatingmechanism is movable as the base is raised and lowered on the post.

An arc lighting a central supporting carried by said post,

apparatus comprising post, a refiector dome a reflector attached to thelower edge of said dome, a lamp base slidable on said post,electrode-operating mechanism carried by said base and normally housedwithin the dome, movable electrodes depending from said operatingmec-hanism through said base, and stationary electrodes supported belowsaid base in alinement with the movable electrodes.

G. An arc lighting apparatus comprising a central supporting post, areflector dome carried by said post, a reflector attached to the loweredge of said dome, a lamp base slidable on said post, a counterpoisecarried by said post and connected to said base to counterbalance theweight of said base and parts carried thereby, electrode-operatingmechanism mounted on said base and normally housed within the dome,movable electrodes depending from said operating mechanism through saidbase, and stationary electrodes supported belovs7 said base in alinementwith the movable electrodes.

7. An arc lighting apparatus comprising a central supporting post, aspider secured to theupper end of said post, a reflector dome having itsupper edge secured to said spider, a reflector attached to the loweredge of said dome, a lamp base slidable on said post,electrode-operating mechanism carried by said base and normally housedwithin the dome, movable electrodes depending from said operatingmechanism through said base, and stationary electrodes supported belowsaid base in alinement with the movable electrodes.

8. An arc lighting apparatus comprising a central supporting post, aspider fixed to the upper end of said post, a reflector dome having itsupper edge secured to said spider, a reflector attached to the loweredge of said dome, a lamp base slidable on said post, a counterpoisecarried by said post and connected to said basel to counterbalance theweight of the base and parts mounted thereon,v electrode-operatingmechanism carried by said basev and normally housed within the dome,movable electrodes depending from saidV operating mechanism through saidbase, and stationary electrodes supported below said base in alinementwith the movable electrodes.

9. An arc lighting apparatus comprising a central supporting postiy areflector dome carried by said post, areflector attached to theloweredge of said dome, a lamp base slidable' on saidpost,1 a plurality oflamp frames mounted on said base', electrode-operating mechanism carriedby said frames, movable electrodes depending from said mechanism throughthe base, and stationary electrodes supported below said base inalinement with the movable electrodes.

10.V An arc lighting apparatus comprising n a central supportingpost, aspider secured to the upper end of said post, a reflector dome havingits upper edge secured to said spider, a reflector attached to the loweredge of said dome, a lamp base slidable on said post, a plurality oflamp frames mounted on said base, electrode-operating mechanism carriedby said frames, movable electrodes depending from said mechanism throughthe base, and stationary electrodes supported below said base inalinement with the movable electrodes.

ll. An arc lighting apparatus comprising a central supporting post, areflector fixed to and carried by said post, a lamp base slidable onsaid nest, a counterpoise carried by the upper end of said postandconnected to said base to counterbalance the weight of said base and theparts carried thereby, a plurality of lai-np frames mounted on saidbase, electrode-operating mechanism carried by said frames, movableelectrodes depending from said n echanism through the base, andstationary electrodes supported below said base in alinement with themovable electrodes.

l2. An arc lighting apparatus comprising a central supporting post, areflector dome carried by said post, a reflector attached to the loweredge of said dome, a lamp base slidable on said pest, a counterpoisecarried by the upper end ef said post and connected to said base tocounterbalance the weight thereof and the parts carried thereby, aplurality of lamp frames mounted. on said base, electrode-operatingmechanism carried by said frames, movable electrodes depending from saidmechanism through the base, and stationary electrodes .supported belowsaid base in alinement with the movable electrodes.

13. An arc lighting `apparatus comprising a central supporting post, aspider fixed to the upper end of said post, a reflector dome having itsupper edge secured to said spider, a reflector attached to the loweredge of said dome, a lamp base slidable. on said post, a counterpoisecarried by the upper end of said post and connected to said base tocounterbalance the weight of said base and the parts carried thereby,plurality of lamp frames mount-ed on said base, electrode-operatingmechanism carried by said frames, movable electrodes depending from saidmechanism through the base, and stationary electrodes supported belowsaid base in alinement with the movable electrodes.

14. An arc lighting apparatus comprising a central supporting post, areflector dome carried by said post, a reflector attached to the loweredge of said dome, a lamp base slidable onsaid post, a plurality of lampframes mounted on said base and havingtail members extending downwardlythrough said base, electrode-operating mechanism carried by said framesand normally housed within the dome, movable electrodes depending fromsaid mechanism through the base, and stationary electrodes supported bysaid tail members below said base in alinemcnt with the movableelectrodes.

15. An arc lighting apparatus comprising a central supporting post, areflector fixed to and carried by said post, a lamp base slidable onsaid post, a plurality of lamp frames mounted on said base and havingtail members extending downwardly through said base, electrode-operatingmechanism carried by said frames, movable electrodes depending from saidmechanism through the base, stationary electrodes supported by said tailmembers belowl said base in alinement with the movable electrodes, andan ash tray secured to the lower ends of said tail members.

16. An arc lighting apparatus comprising a central supporting post, areflector dome carried by said post, a reflector attached to the loweredge of said dome, a lamp base slidable on said post, a plurality oflamp iframes mounted on said base and havingtail members extendingdownwardly through said base, electrode-operating mechanism carried bysaid base and normally housed within the dome, movable electrodesdepending from said mechanism through the base, stationary electrodessupported by said tail members below said base in alincment with themovable electrodes, and an ash tray secured to thel lower ends of saidtail members.

` 17. An arc lighting apparatus comprising a central supporting post. aspider secured to the upper end of said post, a reflector dome havingits upper edge secured to said spider, a reflector attached to the loweredge of said dome, a lamp base slidable on said post, a plurality oflamp frames mounted on said base and having tail members extendingdownwardly therethrough. electrode-oporating mechanism carried by saidJframes and normally housed within said dome, movable electrodesdepending from said mechanism through the base, stationary electrodessupported by said tail members below said base in alinement with themovable electrodes, and an ash tray secured to the lower ends of saidtail members.

18. An arc lighting apparatus comprising a central supporting post, a`reflector dome carried by said post, a reflector attached to the loweredge ot said dome, a lamp base slidable on said post, a plurality oflamp frames mounted on said base and having tail members extendingdownwardly through said base, electrode operating-mechanism carried bysaid frames and normally housed within said dome, movable electrodesdepending from said mechanism through the base, stationary electrodessupported by said tail members below said base in alinement with themovable electrodes, a counterpoise carried by the upper end of said postand connected to said base to balance the weight of said base and themechanism carried thereby, and an ash tray secured to the lower ends ofsaid tail members.

19. An arc lighting apparatus comprising a central supporting post, aspider fastened to the upper end of said post, a reflector dome havingits upper edge secured i'o said spider. a reflector attached to thelower edge of said dome, a lamp base slidable on sald post, acounterpoise carried by the upper end of said post and connected to saidbase to counterbalance the weight thereof and the parts carried thereby.a plurality of lamv frames mounted on said base and having tail membersextending downwardly through said base, electrode-operating mechanismcarried by said frame, movable electrodes depending from said mechanismthrough the base, stationary electrodes supported by said tail membersbelow said base in alinement with the movable electrodes, and an ashtray secured to the lower ends of said tail members.

20. An'arc lighting apparatus comprising a central supporting post, areflector fixed to and carried by said post, a lamp base slidable onsaid post, electrode-operating mechanism supported on said base, movableelectrodes depending from said mechanism. through said base, andstationary electrodes supported below said base in alinement with themovable electrodes, said reflector having a central opening throughwhich said mechanism is movable as the base is raised and lowered, landthe edge of said base being normally positioned adjacent the upper edgeot said refiector and spaced from the reflector to permit the escape ofarc fumes therebetween.

, 21. An arc lighting apparatus comprising a central supporting post, areflector dome carried by said post, a reflector attached to the loweredge of said dome, al lamp base slidable on said post,electrode-operating mechanism supported on said base and normally housedwithin said dome, movable electrodes depending from said mechanismthrough said base, and stationary electrodes supported below said basein alinement with the movable electrodes, the edge of said base beingnormally spaced from the reflector to permit the escape of arc fumestherebetween.

22 An arc lighting apparatus comprising a central supporting post, aspider carried by the upper end of said post, a reflector dome havingits upper edge secured to said spider, a reflector secured to the loweredge of said dome, a lamp base slidable on said post, electrode-operatinmechanism supported on said base, mova le electrodes depending from saidmechanism through said base, and stationary electrodes supported belowsaid base in alinement with the movable electrodes, the edge of saidbase being' normally spaced from the reflector to permit the escape ofarc fumes therebetween into the reflector dome.

23. An arc lighting apparatus comprising a cent al supporting post, areflector fixed to and carried by said post, a lamp base slidable onsaid post, a plurality of spacing` lingers carried by said base at theedge' thereof and adapted to Contact with the reflector adjacent theupper edge thereof when the base is in normal position, to space theedge of said base from the retlec tor, electrode-operating mechanismsupported on base, movable electrodes depending from said mechanismthrough said base, and stationary electrodes supported below said basein alinement with the movable electrodes.

2l. An arc lighting appara-tus comprising a central supporting post, areflector dome carried by said post, a reector secured to the lower edgeof said dome, a lamp base slidable on lsaid post, a plurality of spacingfingers carried by the base adjacent the edge thereof and adapted tocontact with the reflector to space the edge of the lamp base from saidreflector, electrodeoperating mechanism supported on said base andnormally housed within the dome, movable electrodes depending from saidmechanism through said base, and stationary electrodes supported belowsaid base in alinement with the movable electrodes.

25. An arc lighting apparatus compris ing a central tubular supportingpost, a refiectorlixed to and carried by said post, and having a centralopening through which the lamp-operating mechanism is movable, a lampbase slidable on said post, a counterpoise carried by the upper end ofsaid post and connected to said base to balance the .veight of said baseand the parts carried thereby, electrode-operating mechanism supportedon said base, movable electrodes depending from said operating mechanismthrough said base, and stationary electrodes supported below said basein alinement with said movable electrodes, and electrical conductorspassing through said tubular post for supplying current to saidelectrodes.

26. An arc lighting apparatus comprising a central tubular supportingpost, a lamp base slidable on said post, an ash tray fixed with respectto said base, electrode operating mechanism supported on said base,movable electrodes depending from said operating mechanism through saidbase, stationary electrodes supported between said base and ash tray inalinemeniwith said movable electrodes, a reflector fixed to and carriedby said post and having a central opening through which the.`electrole-operating mechanism is movable as the base is raised andlowered on the post, a plurality of switches carried on said ash tr andelectrically connected with the circuits of said lamp, and electricalconductors leading to said switches and passing through said tubularpost.

27. In an arc lamp, the combination of a movable electrode, a. clutchcooperating therewith, a clutch rod, a pair of clamping members clampedabout said electrode, one ol" said members ha Ying recesses therein, astrip of insulation applied to said member covering said recesses, a rodguide having a portion lying against said insulation and provided withprojections litting said recesses, said guide having an arm with a holethrough which the rod extends, and a bolt extending through said guideand clamping members to clamp them together.

28. An arc lighting apparatus comprising a central supporting post, alamp base slidable on said post, a plurality of lamp frames mounted onsaid base and inclined to the vertical, the lower ends of said framesbeing spaced further from the post than the upper ends,electrode-operating mechanism carried by said frames, movable electrodesdepending from said mechanism through the base, and stationaryelectrodes supported below said base in alinement with the movableelectrodes and in parallelism with the frames, and a rellector fixed toand carried by said post and having a central opening through which saidmechanism is movable as the base is raised and lowered on the post.

JAMES H. VVAGENHORST.

